1. Field of the Invention
The invention relates generally to a method for sterilizing liquids and, more particularly, the invention relates to a method for sterilizing a tattooing solution through irradiation.
2. Description of the Background Art
Endoscopists have used tattoos to permanently mark specific sites in the colon that require follow-up examination. Such marking enables the endoscopist to easily find the marked location and perform the follow-up exam. Since tattooing with a substance such as india ink is permanent, such marking allows follow-up examinations to be performed over a long period of time. As such, the injected india ink may remain in the colonic tissue for 20 to 30 years. Alternatively, a tattoo may be used for short term, preoperative marking wherein an endoscopist can identify and mark regions of concern in the colon and, during an operation, the marked region of the colon can be easily identified by the surgeon. In both cases, concerns were raised about the safety of the use of india ink as a colonic marker. There were reports that the use of unsterilized or improperly sterilized india ink caused influenza, infection, phlegmonous gastritis, fat necrosis with inflammatory pseudotumor and abscesses.
To combat the problems associated with the use of india ink for colonic tattooing, physicians have begun requiring the ink be sterilized prior to use. One sterilization process that has been used combines india ink with bacteriostatic sterile water, then filters the solution with a 5 xcexcm Travenol particulate filter, and lastly autoclaves the solution in 10 ml aliquots at 250xc2x0 F. for 40 minutes. This process is messy, time consuming and the use of the 5 xcexcm filter can remove a substantial amount of carbon black from the solution. Additionally, there is no standardized filtration process for sterilizing india ink. Consequently, the degree of sterilization varies from batch to batch.
Therefore, a need exists in the art for a method of sterilizing tattooing solutions that is simple, less time consuming, and repeatable from batch to batch.
The disadvantages heretofore associated with the prior art are overcome by a method of sterilizing tattooing solutions (e.g., india ink) through irradiation. In an illustrative embodiment of the invention, india ink is mixed in a saline solution, the mixture is covered with a paraffin film and sonicated, the mixture is then filtered through a 20 micron filter, then packaged and sealed. The packaged product is exposed to gamma radiation sufficient to sterilize the india ink solution.